Deploying Scalable NGINX Applications on Kubernetes Using ReplicationController and Services with Bhashwanth & Chinnu

🧑‍💻 Blog Title:

"Kubernetes Services in Action: Deploying and Exposing NGINX with ReplicationController (ft. Bhashwanth & Chinnu)"

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📚 Table of Contents:

1. Introduction

2. Prerequisites

3. Creating the ReplicationController

4. Exposing the Pods Using Services

   • ClusterIP

   • NodePort

   • LoadBalancer

5. Accessing the Application

6. Output Commands & Snapshots

7. Conclusion

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1. Introduction

This guide walks you through how to:

• Deploy a ReplicationController

• Expose your Pods using ClusterIP, NodePort, and LoadBalancer

• Use Kubernetes concepts in a fun way by naming components after Tollywood-style names — Bhashwanth and Chinnu.

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2. Prerequisites

• Kubernetes cluster (minikube or cloud-based like EKS, AKS, GKE)

• kubectl configured

• Basic YAML understanding

Directory structure:

bashCopyEditReplication/
├── clusterip-service.yml
├── nodeport-service.yml
├── loadbalancer-service.yml
└── replication-controller.yml

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3. ReplicationController YAML

📄 replication-controller.yml:

yamlCopyEditapiVersion: v1
kind: ReplicationController
metadata:
  name: bhashwanth-controller
  labels:
    app: bhashwanth
spec:
  replicas: 3
  selector:
    actor: chinnu
  template:
    metadata:
      labels:
        actor: chinnu
    spec:
      containers:
        - name: chinnu-container
          image: nginx
          ports:
            - containerPort: 80
      nodeSelector:
        service: worker-1

🎯 This creates 3 nginx pods labeled with actor: chinnu.

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4. Exposing Pods with Services

🟡 A. ClusterIP Service

📄 clusterip-service.yml

yamlCopyEditapiVersion: v1
kind: Service
metadata:
  name: bhashwanth-clusterip-service
  labels:
    actor: bhashwanth
spec:
  type: ClusterIP
  selector:
    actor: chinnu
  ports:
    - port: 80
      targetPort: 80

⛓️ Internal access only.

---

🔵 B. NodePort Service

📄 nodeport-service.yml

yamlCopyEditapiVersion: v1
kind: Service
metadata:
  name: bhashwanth-nodeport-service
  labels:
    actor: bhashwanth
spec:
  type: NodePort
  selector:
    actor: chinnu
  ports:
    - port: 80
      targetPort: 80
      nodePort: 30005

🌐 Access app via:

cppCopyEdithttp://<Node-IP>:30005

---

🟢 C. LoadBalancer Service

📄 loadbalancer-service.yml

yamlCopyEditapiVersion: v1
kind: Service
metadata:
  name: bhashwanth-loadbalancer-service
  labels:
    actor: bhashwanth
spec:
  type: LoadBalancer
  selector:
    actor: chinnu
  ports:
    - port: 80
      targetPort: 80

🚀 Automatically creates an external LoadBalancer (on supported cloud providers).

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5. Apply All Configurations

bashCopyEditkubectl apply -f replication-controller.yml
kubectl apply -f clusterip-service.yml
kubectl apply -f nodeport-service.yml
kubectl apply -f loadbalancer-service.yml

✅ Verify Resources:

bashCopyEditkubectl get rc
kubectl get pods
kubectl get svc

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6. Output Example

bashCopyEditkubectl get pods
NAME                          READY   STATUS    RESTARTS   AGE
bhashwanth-controller-abc     1/1     Running   0          20s
...

kubectl get svc
NAME                          TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
bhashwanth-clusterip-service  ClusterIP      10.96.0.1       <none>        80/TCP           1m
bhashwanth-nodeport-service   NodePort       10.96.0.2       <none>        80:30005/TCP     1m
bhashwanth-loadbalancer-service LoadBalancer 10.96.0.3       <pending>      80:xxxxx/TCP     1m

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7. Conclusion

You've now:

• Created a ReplicationController for nginx

• Managed Pods with chinnu labels

• Exposed the app via ClusterIP, NodePort, and LoadBalancer

• Understood practical K8s service types using a fun name twist

🎉 Now you're ready to scale your K8s deployment like a blockbuster hit!